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2018-03-27powerpc/rfi-flush: Make it possible to call setup_rfi_flush() againMichael Ellerman
For PowerVM migration we want to be able to call setup_rfi_flush() again after we've migrated the partition. To support that we need to check that we're not trying to allocate the fallback flush area after memblock has gone away (i.e., boot-time only). Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-27powerpc/rfi-flush: Move the logic to avoid a redo into the debugfs codeMichael Ellerman
rfi_flush_enable() includes a check to see if we're already enabled (or disabled), and in that case does nothing. But that means calling setup_rfi_flush() a 2nd time doesn't actually work, which is a bit confusing. Move that check into the debugfs code, where it really belongs. Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-27powerpc/perf: Add blacklisted events for Power9 DD2.2Madhavan Srinivasan
These events either do not count, or do not count correctly, so to prevent user confusion block counting them at all. Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com> [mpe: Change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-27powerpc/perf: Add blacklisted events for Power9 DD2.1Madhavan Srinivasan
These events either do not count, or do not count correctly, so to prevent user confusion block counting them at all. Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com> [mpe: Change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-27powerpc/perf: Infrastructure to support addition of blacklisted eventsMadhavan Srinivasan
Introduce code to support addition of blacklisted events for a processor version. Blacklisted events are events that are known to not count correctly on that CPU revision, and so should be prevented from being counted so as to avoid user confusion. A 'pointer' and 'int' variable to hold the number of events are added to 'struct power_pmu', along with a generic function to loop through the list to validate the given event. Generic function 'is_event_blacklisted' is called in power_pmu_event_init() to detect and reject early. Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-27powerpc/perf: Prevent kernel address leak via perf_get_data_addr()Madhavan Srinivasan
Sampled Data Address Register (SDAR) is a 64-bit register that contains the effective address of the storage operand of an instruction that was being executed, possibly out-of-order, at or around the time that the Performance Monitor alert occurred. In certain scenario SDAR happen to contain the kernel address even for userspace only sampling. Add checks to prevent it. Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-27powerpc/perf: Prevent kernel address leak to userspace via BHRB bufferMadhavan Srinivasan
The current Branch History Rolling Buffer (BHRB) code does not check for any privilege levels before updating the data from BHRB. This could leak kernel addresses to userspace even when profiling only with userspace privileges. Add proper checks to prevent it. Acked-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-27powerpc/perf: Fix kernel address leak via sampling registersMichael Ellerman
Current code in power_pmu_disable() does not clear the sampling registers like Sampling Instruction Address Register (SIAR) and Sampling Data Address Register (SDAR) after disabling the PMU. Since these are userspace readable and could contain kernel addresses, add code to explicitly clear the content of these registers. Also add a "context synchronizing instruction" to enforce no further updates to these registers as suggested by Power ISA v3.0B. From section 9.4, on page 1108: "If an mtspr instruction is executed that changes the value of a Performance Monitor register other than SIAR, SDAR, and SIER, the change is not guaranteed to have taken effect until after a subsequent context synchronizing instruction has been executed (see Chapter 11. "Synchronization Requirements for Context Alterations" on page 1133)." Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com> [mpe: Massage change log and add ISA reference] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-27powerpc/64: Call H_REGISTER_PROC_TBL when running as a HPT guest on POWER9Paul Mackerras
On POWER9, since commit cc3d2940133d ("powerpc/64: Enable use of radix MMU under hypervisor on POWER9", 2017-01-30), we set both the radix and HPT bits in the client-architecture-support (CAS) vector, which tells the hypervisor that we can do either radix or HPT. According to PAPR, if we use this combination we are promising to do a H_REGISTER_PROC_TBL hcall later on to let the hypervisor know whether we are doing radix or HPT. We currently do this call if we are doing radix but not if we are doing HPT. If the hypervisor is able to support both radix and HPT guests, it would be entitled to defer allocation of the HPT until the H_REGISTER_PROC_TBL call, and to fail any attempts to create HPTEs until the H_REGISTER_PROC_TBL call. Thus we need to do a H_REGISTER_PROC_TBL call when we are doing HPT; otherwise we may crash at boot time. This adds the code to call H_REGISTER_PROC_TBL in this case, before we attempt to create any HPT entries using H_ENTER. Fixes: cc3d2940133d ("powerpc/64: Enable use of radix MMU under hypervisor on POWER9") Cc: stable@vger.kernel.org # v4.11+ Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Reviewed-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-26powerpc/64s: Fix i-side SLB miss bad address handler saving nonvolatile GPRsNicholas Piggin
The SLB bad address handler's trap number fixup does not preserve the low bit that indicates nonvolatile GPRs have not been saved. This leads save_nvgprs to skip saving them, and subsequent functions and return from interrupt will think they are saved. This causes kernel branch-to-garbage debugging to not have correct registers, can also cause userspace to have its registers clobbered after a segfault. Fixes: f0f558b131db ("powerpc/mm: Preserve CFAR value on SLB miss caused by access to bogus address") Cc: stable@vger.kernel.org # v4.9+ Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-26kbuild: Use ls(1) instead of stat(1) to obtain file sizeMichael Forney
stat(1) is not standardized and different implementations have their own (conflicting) flags for querying the size of a file. ls(1) provides the same information (value of st.st_size) in the 5th column, except when the file is a character or block device. This output is standardized[0]. The -n option turns on -l, which writes lines formatted like "%s %u %s %s %u %s %s\n", <file mode>, <number of links>, <owner name>, <group name>, <size>, <date and time>, <pathname> but instead of writing the <owner name> and <group name>, it writes the numeric owner and group IDs (this avoids /etc/passwd and /etc/group lookups as well as potential field splitting issues). The <size> field is specified as "the value that would be returned for the file in the st_size field of struct stat". To avoid duplicating logic in several locations in the tree, create scripts/file-size.sh and update callers to use that instead of stat(1). [0] http://pubs.opengroup.org/onlinepubs/9699919799/utilities/ls.html#tag_20_73_10 Signed-off-by: Michael Forney <forney@google.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-03-26kbuild: rename built-in.o to built-in.aNicholas Piggin
Incremental linking is gone, so rename built-in.o to built-in.a, which is the usual extension for archive files. This patch does two things, first is a simple search/replace: git grep -l 'built-in\.o' | xargs sed -i 's/built-in\.o/built-in\.a/g' The second is to invert nesting of nested text manipulations to avoid filtering built-in.a out from libs-y2: -libs-y2 := $(filter-out %.a, $(patsubst %/, %/built-in.a, $(libs-y))) +libs-y2 := $(patsubst %/, %/built-in.a, $(filter-out %.a, $(libs-y))) Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2018-03-24Merge branch 'linus' into x86/dma, to resolve a conflict with upstreamIngo Molnar
Conflicts: arch/x86/mm/init_64.c Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-24Merge branch 'topic/ppc-kvm' into nextMichael Ellerman
This brings in two series from Paul, one of which touches KVM code and may need to be merged into the kvm-ppc tree to resolve conflicts.
2018-03-23Merge tag 'kvm-ppc-fixes-4.16-3' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into kvm-master PPC KVM fix - Fix a bug causing occasional machine check exceptions on POWER8 hosts, introduced in 4.16-rc1.
2018-03-24KVM: PPC: Book3S HV: Work around TEXASR bug in fake suspend statePaul Mackerras
This works around a hardware bug in "Nimbus" POWER9 DD2.2 processors, where the contents of the TEXASR can get corrupted while a thread is in fake suspend state. The workaround is for the instruction emulation code to use the value saved at the most recent guest exit in real suspend mode. We achieve this by simply not saving the TEXASR into the vcpu struct on an exit in fake suspend state. We also have to take care to set the orig_texasr field only on guest exit in real suspend state. This also means that on guest entry in fake suspend state, TEXASR will be restored to the value it had on the last exit in real suspend state, effectively counteracting any hardware-caused corruption. This works because TEXASR may not be written in suspend state. With this, the guest might see the wrong values in TEXASR if it reads it while in suspend state, but will see the correct value in non-transactional state (e.g. after a treclaim), and treclaim will work correctly. With this workaround, the code will actually run slightly faster, and will operate correctly on systems without the TEXASR bug (since TEXASR may not be written in suspend state, and is only changed by failure recording, which will have already been done before we get into fake suspend state). Therefore these changes are not made subject to a CPU feature bit. Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-24KVM: PPC: Book3S HV: Work around XER[SO] bug in fake suspend modeSuraj Jitindar Singh
This works around a hardware bug in "Nimbus" POWER9 DD2.2 processors, where a treclaim performed in fake suspend mode can cause subsequent reads from the XER register to return inconsistent values for the SO (summary overflow) bit. The inconsistent SO bit state can potentially be observed on any thread in the core. We have to do the treclaim because that is the only way to get the thread out of suspend state (fake or real) and into non-transactional state. The workaround for the bug is to force the core into SMT4 mode before doing the treclaim. This patch adds the code to do that, conditional on the CPU_FTR_P9_TM_XER_SO_BUG feature bit. Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-24KVM: PPC: Book3S HV: Work around transactional memory bugs in POWER9Paul Mackerras
POWER9 has hardware bugs relating to transactional memory and thread reconfiguration (changes to hardware SMT mode). Specifically, the core does not have enough storage to store a complete checkpoint of all the architected state for all four threads. The DD2.2 version of POWER9 includes hardware modifications designed to allow hypervisor software to implement workarounds for these problems. This patch implements those workarounds in KVM code so that KVM guests see a full, working transactional memory implementation. The problems center around the use of TM suspended state, where the CPU has a checkpointed state but execution is not transactional. The workaround is to implement a "fake suspend" state, which looks to the guest like suspended state but the CPU does not store a checkpoint. In this state, any instruction that would cause a transition to transactional state (rfid, rfebb, mtmsrd, tresume) or would use the checkpointed state (treclaim) causes a "soft patch" interrupt (vector 0x1500) to the hypervisor so that it can be emulated. The trechkpt instruction also causes a soft patch interrupt. On POWER9 DD2.2, we avoid returning to the guest in any state which would require a checkpoint to be present. The trechkpt in the guest entry path which would normally create that checkpoint is replaced by either a transition to fake suspend state, if the guest is in suspend state, or a rollback to the pre-transactional state if the guest is in transactional state. Fake suspend state is indicated by a flag in the PACA plus a new bit in the PSSCR. The new PSSCR bit is write-only and reads back as 0. On exit from the guest, if the guest is in fake suspend state, we still do the treclaim instruction as we would in real suspend state, in order to get into non-transactional state, but we do not save the resulting register state since there was no checkpoint. Emulation of the instructions that cause a softpatch interrupt is handled in two paths. If the guest is in real suspend mode, we call kvmhv_p9_tm_emulation_early() to handle the cases where the guest is transitioning to transactional state. This is called before we do the treclaim in the guest exit path; because we haven't done treclaim, we can get back to the guest with the transaction still active. If the instruction is a case that kvmhv_p9_tm_emulation_early() doesn't handle, or if the guest is in fake suspend state, then we proceed to do the complete guest exit path and subsequently call kvmhv_p9_tm_emulation() in host context with the MMU on. This handles all the cases including the cases that generate program interrupts (illegal instruction or TM Bad Thing) and facility unavailable interrupts. The emulation is reasonably straightforward and is mostly concerned with checking for exception conditions and updating the state of registers such as MSR and CR0. The treclaim emulation takes care to ensure that the TEXASR register gets updated as if it were the guest treclaim instruction that had done failure recording, not the treclaim done in hypervisor state in the guest exit path. With this, the KVM_CAP_PPC_HTM capability returns true (1) even if transactional memory is not available to host userspace. Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-24powerpc/powernv: Provide a way to force a core into SMT4 modePaul Mackerras
POWER9 processors up to and including "Nimbus" v2.2 have hardware bugs relating to transactional memory and thread reconfiguration. One of these bugs has a workaround which is to get the core into SMT4 state temporarily. This workaround is only needed when running bare-metal. This patch provides a function which gets the core into SMT4 mode by preventing threads from going to a stop state, and waking up those which are already in a stop state. Once at least 3 threads are not in a stop state, the core will be in SMT4 and we can continue. To do this, we add a "dont_stop" flag to the paca to tell the thread not to go into a stop state. If this flag is set, power9_idle_stop() just returns immediately with a return value of 0. The pnv_power9_force_smt4_catch() function does the following: 1. Set the dont_stop flag for each thread in the core, except ourselves (in fact we use an atomic_inc() in case more than one thread is calling this function concurrently). 2. See how many threads are awake, indicated by their requested_psscr field in the paca being 0. If this is at least 3, skip to step 5. 3. Send a doorbell interrupt to each thread that was seen as being in a stop state in step 2. 4. Until at least 3 threads are awake, scan the threads to which we sent a doorbell interrupt and check if they are awake now. This relies on the following properties: - Once dont_stop is non-zero, requested_psccr can't go from zero to non-zero, except transiently (and without the thread doing stop). - requested_psscr being zero guarantees that the thread isn't in a state-losing stop state where thread reconfiguration could occur. - Doing stop with a PSSCR value of 0 won't be a state-losing stop and thus won't allow thread reconfiguration. - Once threads_per_core/2 + 1 (i.e. 3) threads are awake, the core must be in SMT4 mode, since SMT modes are powers of 2. This does add a sync to power9_idle_stop(), which is necessary to provide the correct ordering between setting requested_psscr and checking dont_stop. The overhead of the sync should be unnoticeable compared to the latency of going into and out of a stop state. Because some objected to incurring this extra latency on systems where the XER[SO] bug is not relevant, I have put the test in power9_idle_stop inside a feature section. This means that pnv_power9_force_smt4_catch() WILL NOT WORK correctly on systems without the CPU_FTR_P9_TM_XER_SO_BUG feature bit set, and will probably hang the system. In order to cater for uses where the caller has an operation that has to be done while the core is in SMT4, the core continues to be kept in SMT4 after pnv_power9_force_smt4_catch() function returns, until the pnv_power9_force_smt4_release() function is called. It undoes the effect of step 1 above and allows the other threads to go into a stop state. Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-24powerpc: Add CPU feature bits for TM bug workarounds on POWER9 v2.2Paul Mackerras
This adds a CPU feature bit which is set for POWER9 "Nimbus" DD2.2 processors which will be used to enable the hypervisor to assist hardware with the handling of checkpointed register values while the CPU is in suspend state, in order to work around hardware bugs. The hardware assistance for these workarounds introduced a new hardware bug relating to the XER[SO] bit. We add a separate feature bit for this bug in case future chips fix it while still requiring the hypervisor assistance with suspend state. When the dt_cpu_ftrs subsystem is in use, the software assistance can be enabled using a "tm-suspend-hypervisor-assist" node in the device tree, and a "tm-suspend-xer-so-bug" node enables the workarounds for the XER[SO] bug. In the absence of such nodes, a quirk enables both for POWER9 "Nimbus" DD2.2 processors. Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-24powerpc: Free up CPU feature bits on 64-bit machinesPaul Mackerras
This moves all the CPU feature bits that are only used on 32-bit machines to the top 20 bits of the CPU feature word and arranges for them to be defined only in 32-bit builds. The features that are common to 32-bit and 64-bit machines are moved to bits 0-11 of the CPU feature word. This means that for 64-bit platforms, bits 44-63 can now be used for new features that only exist on 64-bit machines. (These bit numbers are counting from the right, i.e. the LSB is bit 0.) Because CPU_FTR_L3_DISABLE_NAP moved from the low 16 bits to the high 16 bits, we have to adjust some assembly code. Also, CPU_FTR_EMB_HV moved from the high 16 bits to the low 16 bits. Note that CPU_FTR_REAL_LE only applies to 64-bit chips, because only 64-bit chips (POWER6, 7, 8, 9) have a true little-endian mode that is a CPU execution mode as opposed to being a page attribute. With this we now have 20 free CPU feature bits on 64-bit machines. Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-24powerpc: Book E: Remove unused CPU_FTR_L2CSR bitPaul Mackerras
The CPU_FTR_L2CSR bit is never tested anywhere, so let's reclaim the bit. The last usage was removed in 86d63363defc ("powerpc/e500mc: Remove dead L2 flushing code in idle_e500.S") (Jun 2015). Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-24powerpc: Use feature bit for RTC presence rather than timebase presencePaul Mackerras
All PowerPC CPUs other than the original PPC601 have a timebase register rather than the "real-time clock" (RTC) register that the PPC601 (and the original POWER and POWER2 CPUs) had. Currently we have a CPU feature bit to indicate the presence of the timebase, but it makes more sense to use a bit to indicate the unusual situation rather than the common situation. This therefore defines a CPU_FTR_USE_RTC bit in place of the CPU_FTR_USE_TB bit, and arranges for it to be set on PPC601 systems. Signed-off-by: Paul Mackerras <paulus@ozlabs.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-23powerpc/mm: Fixup tlbie vs store ordering issue on POWER9Aneesh Kumar K.V
On POWER9, under some circumstances, a broadcast TLB invalidation might complete before all previous stores have drained, potentially allowing stale stores from becoming visible after the invalidation. This works around it by doubling up those TLB invalidations which was verified by HW to be sufficient to close the risk window. This will be documented in a yet-to-be-published errata. Fixes: 1a472c9dba6b ("powerpc/mm/radix: Add tlbflush routines") Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> [mpe: Enable the feature in the DT CPU features code for all Power9, rename the feature to CPU_FTR_P9_TLBIE_BUG per benh.] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-23powerpc/mm/radix: Move the functions that does the actual tlbie closerAneesh Kumar K.V
No functionality change. Just code movement to ease code changes later Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-23powerpc/mm/radix: Remove unused codeAneesh Kumar K.V
These function are not used in the code. Remove them. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-23powerpc/mm: Workaround Nest MMU bug with TLB invalidationsBenjamin Herrenschmidt
On POWER9 the Nest MMU may fail to invalidate some translations when doing a tlbie "by PID" or "by LPID" that is targeted at the TLB only and not the page walk cache. This works around it by forcing such invalidations to escalate to RIC=2 (full invalidation of TLB *and* PWC) when a coprocessor is in use for the context. Fixes: 03b8abedf4f4 ("cxl: Enable global TLBIs for cxl contexts") Cc: stable@vger.kernel.org # v4.15+ Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Balbir Singh <bsingharora@gmail.com> [balbirs: fixed spelling and coding style to quiesce checkpatch.pl] Tested-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-23powerpc/mm: Add tracking of the number of coprocessors using a contextBenjamin Herrenschmidt
Currently, when using coprocessors (which use the Nest MMU), we simply increment the active_cpu count to force all TLB invalidations to be come broadcast. Unfortunately, due to an errata in POWER9, we will need to know more specifically that coprocessors are in use. This maintains a separate copros counter in the MMU context for that purpose. NB. The commit mentioned in the fixes tag below is not at fault for the bug we're fixing in this commit and the next, but this fix applies on top the infrastructure it introduced. Fixes: 03b8abedf4f4 ("cxl: Enable global TLBIs for cxl contexts") Cc: stable@vger.kernel.org # v4.15+ Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Tested-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-23KVM: PPC: Book3S HV: Fix duplication of host SLB entriesPaul Mackerras
Since commit 6964e6a4e489 ("KVM: PPC: Book3S HV: Do SLB load/unload with guest LPCR value loaded", 2018-01-11), we have been seeing occasional machine check interrupts on POWER8 systems when running KVM guests, due to SLB multihit errors. This turns out to be due to the guest exit code reloading the host SLB entries from the SLB shadow buffer when the SLB was not previously cleared in the guest entry path. This can happen because the path which skips from the guest entry code to the guest exit code without entering the guest now does the skip before the SLB is cleared and loaded with guest values, but the host values are loaded after the point in the guest exit path that we skip to. To fix this, we move the code that reloads the host SLB values up so that it occurs just before the point in the guest exit code (the label guest_bypass:) where we skip to from the guest entry path. Reported-by: Alexey Kardashevskiy <aik@ozlabs.ru> Fixes: 6964e6a4e489 ("KVM: PPC: Book3S HV: Do SLB load/unload with guest LPCR value loaded") Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-03-23powerpc/64s: Fix lost pending interrupt due to race causing lost update to ↵Nicholas Piggin
irq_happened force_external_irq_replay() can be called in the do_IRQ path with interrupts hard enabled and soft disabled if may_hard_irq_enable() set MSR[EE]=1. It updates local_paca->irq_happened with a load, modify, store sequence. If a maskable interrupt hits during this sequence, it will go to the masked handler to be marked pending in irq_happened. This update will be lost when the interrupt returns and the store instruction executes. This can result in unpredictable latencies, timeouts, lockups, etc. Fix this by ensuring hard interrupts are disabled before modifying irq_happened. This could cause any maskable asynchronous interrupt to get lost, but it was noticed on P9 SMP system doing RDMA NVMe target over 100GbE, so very high external interrupt rate and high IPI rate. The hang was bisected down to enabling doorbell interrupts for IPIs. These provided an interrupt type that could run at high rates in the do_IRQ path, stressing the race. Fixes: 1d607bb3bd60 ("powerpc/irq: Add mechanism to force a replay of interrupts") Cc: stable@vger.kernel.org # v4.8+ Reported-by: Carol L. Soto <clsoto@us.ibm.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-20dma/direct: Handle the memory encryption bit in common codeChristoph Hellwig
Give the basic phys_to_dma() and dma_to_phys() helpers a __-prefix and add the memory encryption mask to the non-prefixed versions. Use the __-prefixed versions directly instead of clearing the mask again in various places. Tested-by: Tom Lendacky <thomas.lendacky@amd.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Joerg Roedel <joro@8bytes.org> Cc: Jon Mason <jdmason@kudzu.us> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Muli Ben-Yehuda <mulix@mulix.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: iommu@lists.linux-foundation.org Link: http://lkml.kernel.org/r/20180319103826.12853-13-hch@lst.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-20powerpc: dts: replace 'linux,stdout-path' with 'stdout-path'Rob Herring
'linux,stdout-path' has been deprecated for some time in favor of 'stdout-path'. Now dtc will warn on occurrences of 'linux,stdout-path'. Search and replace all the of occurrences with 'stdout-path'. Signed-off-by: Rob Herring <robh@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-20powerpc: Use sizeof(*foo) rather than sizeof(struct foo)Markus Elfring
It's slightly less error prone to use sizeof(*foo) rather than specifying the type. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> [mpe: Consolidate into one patch, rewrite change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-20powerpc: Remove unused flush_dcache_phys_range()Matt Brown
The flush_dcache_phys_range() function is no longer used in the kernel. The last usage was removed in c40785ad305b ("powerpc/dart: Use a cachable DART"). This patch removes the function and declaration. Signed-off-by: Matt Brown <matthew.brown.dev@gmail.com> [mpe: Munge change log, include commit that removed last user] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-20lib/raid6/altivec: Add vpermxor implementation for raid6 Q syndromeMatt Brown
This patch uses the vpermxor instruction to optimise the raid6 Q syndrome. This instruction was made available with POWER8, ISA version 2.07. It allows for both vperm and vxor instructions to be done in a single instruction. This has been tested for correctness on a ppc64le vm with a basic RAID6 setup containing 5 drives. The performance benchmarks are from the raid6test in the /lib/raid6/test directory. These results are from an IBM Firestone machine with ppc64le architecture. The benchmark results show a 35% speed increase over the best existing algorithm for powerpc (altivec). The raid6test has also been run on a big-endian ppc64 vm to ensure it also works for big-endian architectures. Performance benchmarks: raid6: altivecx4 gen() 18773 MB/s raid6: altivecx8 gen() 19438 MB/s raid6: vpermxor4 gen() 25112 MB/s raid6: vpermxor8 gen() 26279 MB/s Signed-off-by: Matt Brown <matthew.brown.dev@gmail.com> Reviewed-by: Daniel Axtens <dja@axtens.net> [mpe: Add VPERMXOR macro so we can build with old binutils] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-19scsi: remove the fdomain and fdomain_cs driversChristoph Hellwig
These drivers haven't seen any recent bug fixing and are two of the last drivers using the scsi_module.c infrastruture that has been deprecated 15 years ago. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2018-03-19Merge tag 'v4.16-rc6' into perf/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-03-19KVM: PPC: Book3S HV: Handle 1GB pages in radix page fault handlerPaul Mackerras
This adds code to the radix hypervisor page fault handler to handle the case where the guest memory is backed by 1GB hugepages, and put them into the partition-scoped radix tree at the PUD level. The code is essentially analogous to the code for 2MB pages. This also rearranges kvmppc_create_pte() to make it easier to follow. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-03-19KVM: PPC: Book3S HV: Streamline setting of reference and change bitsPaul Mackerras
When using the radix MMU, we can get hypervisor page fault interrupts with the DSISR_SET_RC bit set in DSISR/HSRR1, indicating that an attempt to set the R (reference) or C (change) bit in a PTE atomically failed. Previously we would find the corresponding Linux PTE and check the permission and dirty bits there, but this is not really necessary since we only need to do what the hardware was trying to do, namely set R or C atomically. This removes the code that reads the Linux PTE and just update the partition-scoped PTE, having first checked that it is still present, and if the access is a write, that the PTE still has write permission. Furthermore, we now check whether any other relevant bits are set in DSISR, and if there are, then we proceed with the rest of the function in order to handle whatever condition they represent, instead of returning to the guest as we did previously. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-03-19KVM: PPC: Book3S HV: Radix page fault handler optimizationsPaul Mackerras
This improves the handling of transparent huge pages in the radix hypervisor page fault handler. Previously, if a small page is faulted in to a 2MB region of guest physical space, that means that there is a page table pointer at the PMD level, which could never be replaced by a leaf (2MB) PMD entry. This adds the code to clear the PMD, invlidate the page walk cache and free the page table page in this situation, so that the leaf PMD entry can be created. This also adds code to check whether a PMD or PTE being inserted is the same as is already there (because of a race with another CPU that faulted on the same page) and if so, we don't replace the existing entry, meaning that we don't invalidate the PTE or PMD and do a TLB invalidation. Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-03-19KVM: PPC: Remove unused kvm_unmap_hva callbackPaul Mackerras
Since commit fb1522e099f0 ("KVM: update to new mmu_notifier semantic v2", 2017-08-31), the MMU notifier code in KVM no longer calls the kvm_unmap_hva callback. This removes the PPC implementations of kvm_unmap_hva(). Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
2018-03-18mm: Add address parameter to arch_validate_prot()Khalid Aziz
A protection flag may not be valid across entire address space and hence arch_validate_prot() might need the address a protection bit is being set on to ensure it is a valid protection flag. For example, sparc processors support memory corruption detection (as part of ADI feature) flag on memory addresses mapped on to physical RAM but not on PFN mapped pages or addresses mapped on to devices. This patch adds address to the parameters being passed to arch_validate_prot() so protection bits can be validated in the relevant context. Signed-off-by: Khalid Aziz <khalid.aziz@oracle.com> Cc: Khalid Aziz <khalid@gonehiking.org> Reviewed-by: Anthony Yznaga <anthony.yznaga@oracle.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-16perf: Fix sibling iterationPeter Zijlstra
Mark noticed that the change to sibling_list changed some iteration semantics; because previously we used group_list as list entry, sibling events would always have an empty sibling_list. But because we now use sibling_list for both list head and list entry, siblings will report as having siblings. Fix this with a custom for_each_sibling_event() iterator. Fixes: 8343aae66167 ("perf/core: Remove perf_event::group_entry") Reported-by: Mark Rutland <mark.rutland@arm.com> Suggested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: vincent.weaver@maine.edu Cc: alexander.shishkin@linux.intel.com Cc: torvalds@linux-foundation.org Cc: alexey.budankov@linux.intel.com Cc: valery.cherepennikov@intel.com Cc: eranian@google.com Cc: acme@redhat.com Cc: linux-tip-commits@vger.kernel.org Cc: davidcc@google.com Cc: kan.liang@intel.com Cc: Dmitry.Prohorov@intel.com Cc: jolsa@redhat.com Link: https://lkml.kernel.org/r/20180315170129.GX4043@hirez.programming.kicks-ass.net
2018-03-15Merge tag 'kvm-ppc-fixes-4.16-2' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into kvm-master Fix for PPC KVM for 4.16 - Fix bug leading to lost IPIs on POWER9 and hence to other CPUs reporting lockups in smp_call_function_many().
2018-03-14powerpc/5200: dts: digsy_mtc.dts: fix rv3029 compatibleAlexandre Belloni
The proper compatible for rv3029 is microcrystal,rv3029. Acked-by: Anatolij Gustschin <agust@denx.de> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-14powerpc/time: stop validating rtc_time in .read_timeAlexandre Belloni
The RTC core is always calling rtc_valid_tm after the read_time callback. It is not necessary to call it just before returning from the callback. Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-14powerpc/64s: Fix NULL AT_BASE_PLATFORM when using DT CPU featuresMichael Ellerman
When running virtualised the powerpc kernel is able to run the system in "compat mode" - which means the kernel and hardware are pretending to userspace that the CPU is an older version than it actually is. AT_BASE_PLATFORM is an AUXV entry that we export to userspace for use when we're running in that mode, which tells userspace the "platform" string for the real CPU version, as opposed to the faked version. Although we don't support compat mode when using DT CPU features, and arguably don't need to set AT_BASE_PLATFORM, the existing cputable based code always sets it even when we're running bare metal. That means the lack of AT_BASE_PLATFORM is a user-visible artifact of the fact that the kernel is using DT CPU features, which we don't want. So set it in the DT CPU features code also. This results in eg: $ LD_SHOW_AUXV=1 /bin/true | grep "AT_.*PLATFORM" AT_PLATFORM: power9 AT_BASE_PLATFORM:power9 Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
2018-03-14powerpc/vas: Add a couple of trace pointsSukadev Bhattiprolu
Add a couple of trace points in the VAS driver Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> [mpe: Add SPDX tag to new header] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-14powerpc/vas: Fix cleanup when VAS is not configuredSukadev Bhattiprolu
When VAS is not configured, unregister the platform driver. Also simplify cleanup by delaying vas debugfs init until we know VAS is configured. Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2018-03-14powerpc/npu-dma.c: Fix crash after __mmu_notifier_register failureMark Hairgrove
pnv_npu2_init_context wasn't checking the return code from __mmu_notifier_register. If __mmu_notifier_register failed, the npu_context was still assigned to the mm and the caller wasn't given any indication that things went wrong. Later on pnv_npu2_destroy_context would be called, which in turn called mmu_notifier_unregister and dropped mm->mm_count without having incremented it in the first place. This led to various forms of corruption like mm use-after-free and mm double-free. __mmu_notifier_register can fail with EINTR if a signal is pending, so this case can be frequent. This patch calls opal_npu_destroy_context on the failure paths, and makes sure not to assign mm->context.npu_context until past the failure points. Signed-off-by: Mark Hairgrove <mhairgrove@nvidia.com> Acked-By: Alistair Popple <alistair@popple.id.au> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>